1. Field of the Invention
The present invention relates generally to preparing blood vessels for a vascular anastomosis procedure and more particularly to a graft vessel preparation device which facilitates precise incision of a graft vessel for an anastomosis procedure.
2. Description of Related Art
Vascular anastomosis is a procedure where two separate blood vessels of a patient are surgically grafted together. The vascular anastomosis procedure is routinely performed during the treatment of a variety of conditions, including coronary artery disease, diseases of the great and peripheral vessels, organ transplantation and other types of trauma. When a patient suffers from coronary-artery disease (CAD), an occlusion or stenosis in a coronary artery restricts blood flow to the heart muscle. In order to treat CAD, the area where the occlusion occurs is bypassed. The area is bypassed through rerouting blood flow by grafting a vessel in the form of either a prosthesis, a harvested artery or a vein. When the vessel is grafted to bypass the blocked coronary artery, the occlusion is avoided and adequate blood flow is restored to the heart muscle. This treatment is known as coronary artery bypass grafting (CABG).
When a CABG is performed, a large incision is made in the chest of a patient and the sternum is separated in order to allow access to the heart of the patient. Moreover, the patient is connected to a heart lung machine which circulates the blood of the patient. After the heart lung machine is connected to the patient, the patient""s heart is stopped in order to perform the vascular anastomosis. However, stopping the patient""s heart is very traumatic to the patient.
In order to minimize the trauma to the patient induced by the CABG, less invasive techniques have been used. These less invasive techniques include performing a series of small incisions in the patient""s chest. Once the incisions are completed, surgery is performed with the aid of visualizing scopes. The less invasive techniques may be performed on a beating heart in order minimize trauma to the patient, thereby avoiding the need for cardiopulmonary bypass.
In both conventional and less invasive CABG techniques, a surgeon sutures one end of the graft vessel to the coronary artery and the other end of the graft vessel to a blood supplying vein or artery, such as the aorta, in order to bypass the occlusion. Prior to suturing the graft vessel to the arteries, called target vessels, an incision is made in the target vessel to allow suturing of the graft vessel to the target vessel. Typically, the surgeon cuts the incision in the target vessel to an appropriate length depending on a size of the graft vessel in order to suture the graft vessel to the target vessel. However, a great amount of skill and time is required in making the incision due to the small size of the graft vessel. Likewise, time and skill is required in aligning the graft vessel to the incision. Performing the anastomosis is further compounded by the small size and the flexible, circular configuration of the of the graft vessel. In addition, the surgeon has difficulties holding and suturing in the graft vessel due to the small size an d the flexible, circular configuration of the blood vessel.
Accordingly, a need exists for an automated method which allows a surgeon to make a precise anastomosis between a graft vessel and a target vessel. This new method should implement a grafting tool which allows a surgeon to control the thin and difficult to handle tissue of the graft and target vessel. Moreover, it would be desirable to implement a grafting tool which allows for making incisions in a graft vessel to establish a predetermined length which matches a length of an incision in a target vessel.
The present invention fills the aforementioned needs by providing a graft vessel preparation device which prepares a graft vessel for a vascular anastomosis procedure. The present invention also provides a method for preparing a graft vessel for a vascular anastomosis procedure using the graft vessel preparation device.
In one embodiment of the present invention, a graft vessel preparation device for preparing a graft vessel is disclosed. The graft vessel preparation device prepares the graft vessel for a vascular anastomosis procedure. The preparation device comprises a spreader, a critical dimension locator and a clamp. The spreader is configured to receive and stretch an end portion of the graft vessel. The critical dimension locator is configured to establish a critical dimension on the graft vessel after the graft vessel is placed over the spreader. The clamp coordinates both the spreader and the critical dimension locator in order to fix the critical dimension on the graft vessel. The critical dimension allows for precise grafting of the graft vessel to a coronary artery during a vascular anastomosis procedure.
In a further embodiment of the present invention, a graft vessel preparation device for preparing a graft vessel for a vascular anastomosis procedure is disclosed. The preparation device comprises a parallelogram linkage, a first spreader arm and a second spreader arm. The first spreader arm and the second spreader arm are mounted on opposing members of the parallelogram linkage such that the first spreader arm and the second spreader arm are parallel to one another. The parallelogram linkage also provides motion to the spreader arms whereby the spreader arms are movable with respect to each other. Also, the spreader arms are configured to receive an end of a graft vessel as the graft vessel is placed on to the graft vessel preparation device. Moreover, the spreader arms separate from one another to establish a critical dimension on the graft vessel.
In another embodiment of the present invention, a graft vessel preparation device for preparing a graft vessel for a vascular anastomosis procedure is disclosed. The graft vessel preparation device includes a base, first and second spreader arms, an extension link and a holding clamp. The base includes a first part and a second part which are movable with respect to each other. The first and second spreader arms are attached to the first and second parts of the base of the graft vessel preparation device. Also, the spreader arms are configured to receive an end of the graft vessel when the graft vessel is placed over the spreader arms. The extension link of the graft vessel preparation device is rotatably attached to the base and is configured to separate the first and second spreader arms. The holding clamp of the graft vessel preparation device is substantially aligned with the extension link and clamps the graft vessel.
In yet another embodiment of the present invention, a method for preparing a graft vessel for an anastomosis procedure using a graft vessel preparation device is disclosed. The graft vessel preparation device includes spreader arms that are movable with respect to each other. The method comprises placing the graft vessel over the spreader arms such that the spreader arms occupy an interior of the graft vessel. Once the graft vessel is placed over the spreader arms, the spreader arms are moved from one another to stretch the graft vessel. A critical dimension is then established once the graft vessel is stretched. The critical dimension is established by moving the spreader arms away from one another with the parallelogram linkage.
In a further embodiment of the present invention, a graft vessel flapper is disclosed. The graft vessel flapper comprises spreader arms which are movable with respect to each other and a clamp. The clamp, which is rotatable with respect to the spreader arms, clamps a graft vessel placed over the spreader arms. In addition, the clamp establishes a critical dimension of the graft vessel.
In another embodiment of the present invention, a method for preparing a graft vessel using a graft vessel preparation device is disclosed. The method includes forming an incision in a target vessel such that an incision perimeter is formed in the target vessel. The graft vessel is then prepared by establishing and maintaining a critical dimension of the graft vessel. The critical dimension is formed on the graft vessel such that the perimeter of the critical dimension is the same as the incision perimeter of the target vessel. The congruity of between the incision perimeter of the target vessel and the perimeter of the of the critical dimension allow for proper grafting of the graft vessel to the target vessel during a vascular anastomosis procedure.
As may be appreciated, the present invention provides a device which allows an automated method for preparing graft vessels for a vascular anastomosis procedure. The present invention precisely and accurately slices a graft vessel such that the graft vessel will graft with a coronary artery during the vascular anastomosis procedure.